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set theory-1

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A  Set  is an unordered collection of objects, known as elements or members of the set. An element ‘a’ belong to a set A can be written as ‘a ∈ A’,  ‘a ∉ A’ denotes that a is not an element of the set A. Representation of a Set A set can be represented by various methods. 3 common methods used for representing set: 1. Statement form. 2. Roaster form or tabular form method. 3. Set Builder method. Statement form In this representation, the well-defined description of the elements of the set is given. Below are some examples of the same. 1. The set of all even number less than 10. 2. The set of the number less than 10 and more than 1. Roster form In this representation, elements are listed within the pair of brackets {} and are separated by commas. Below are two examples. 1. Let N is the set of natural numbers less than 5. N = { 1 , 2 , 3, 4 }. 2. The set of all vowels in the English alphabet. V = { a , e , i , o , u }. Set builder form ...
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Networking

Suppose that everyone in a group of N people wants to communicate secretly with the N–1 others using symmetric key cryptographic system. The communication between any two persons should not be decodable by the others in the group. The number of keys required in the system as a whole to satisfy the confidentiality requirement is (A) 2N (B) N(N – 1) (C) N(N – 1)/2 (D) (N – 1) 2 Answer We need to find the total number of possible pairs from the N given people, each pair will share a key. So, number of ways to choose two persons from N people =  N C 2  = N! / ((N −2)!×2!) =  N(N-1)/2 Therefore, correct answer is Option  (C)
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Operating System

A  bit  in a memory  cache  or virtual  memory  page  that has been modified by the  CPU , but not  yet  written  back to  storage . Auto increment:   In auto-increment addressing mode the address where next data block to be stored is generated automatically depending upon the size of single data item required to store. Self relocating code takes always some address in memory and statement says that this mode is used for self relocating code and  no additional ALU is required  Which of the following is/are true of the auto-increment addressing mode? I. It is useful in creating self-relocating code. II. If it is included in an Instruction Set Architecture, then an additional ALU is required for effective address calculation. III.The amount of increment depends on the size of the data item accessed. (A)  I only (B)  II only (C)  III Only (D)  II an...
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algorithmn

Consider the following pseudo-code fragment, where m is a non-negative integer that has been initialized: p=0; k=0; while(k < m)         p = p + 2 k ;         k=k+1; end while Which of the following is a loop invariant for the while statement? (Note: a loop variant for a while statement is an assertion that is true each time guard is evaluated during the execution of the while statement).
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database

SQL Query; Drop Table : Delete whole structure of the relation, which we cannot be obtain in future Update: use to modify existing record Delete: is used for deleting the record. To remove a relation from an SQL database, we use the ______ command. a) Delete b) Purge c) Remove d) Drop table
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Pascal Language

Pascal:  Pascal is a structured programming language . its came before C.  unlike C, this language can import function without using header file. C extract feature of Pascal Language.
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Cache Mapping

Write through: write through  में  data , cache memory और main  memory के block में एक साथ लिखा जाता है | Write back : write back में data , cache memory में regular  update या change होता रहता है , परन्तु एक particular interval या किसी ख़ास event पर ही data , main memory में update होता है | Write Protected ; Write protected में data न तो delete होता है नहीं modified . Direct Mapping : Main Memory  ये main memory है  जिसकी size 32  words है | (1  byte =1  word ). इस  main memory को  8 fragments में बाटा गया है |  इन fragments को main memory में block  कहा जाता  है |  यहां प्रत्येक block का size 4 words का है | 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 ...
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